A rectangle is $3$ units long. The rectangle is also $6$ units wide. What is its perimeter?
Answer: $3\text{ }$ $6\text{ }$ The perimeter is the total length of all the sides of the shape added together. Add up the lengths of the sides: $ \text{perimeter} = {6} + {3} + {6} + {3} $ $ \text{perimeter} = 18\text{ } $